JPH06200489A - Rope - Google Patents

Abstract

PURPOSE:To provide a high strength rope having light weight, high tenacity and sufficiently high elastic modulus, and substitutable it for metal fiber having high tenacity. CONSTITUTION:This rope is composed of polybenzoxazole fiber having tensile strength of >=4.0GPa and initial elastic modulus of >=140GPa and >=0.9% of a lubricating fats and oils or a resin component among fibers of the rope.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rope suitable for industrial applications such as lifting of loads, and more particularly to a synthetic fiber rope applicable to heavy objects.

[0002]

2. Description of the Related Art Conventionally, polyester, nylon and the like have been used as synthetic fibers for industrial ropes, and particularly for lifting heavy objects, snapping when the rope vibrates or is unloaded due to expansion and contraction of the rope. In order to prevent backing, a metal wire rope having excellent dimensional stability has been used.

However, the wire rope is heavy in its own weight and easily entangles or kinks when a shock is applied, which makes it difficult to handle. Rope made of aramid fiber or high-strength polyethylene fiber has been introduced to overcome such drawbacks.

However, the aramid fiber rope has a drawback that the rope has a large thickness because the specific strength and the specific elastic modulus are not sufficiently high, and the handleability is deteriorated. In addition to the fact that the rope made of high-strength polyethylene fiber has a large thickness, it has poor heat resistance and has a drawback that dimensional stability is deteriorated when it receives heat from an object heated under the hot sun outdoors.

[0005]

SUMMARY OF THE INVENTION The present invention is to provide a rope which is supple and easy to handle, and which has a high strength and a high elastic modulus which has never been obtained.

[0006]

That is, according to the present invention, a polybenzazole fiber having a strength of at least 4.0 GPa and an initial elastic modulus of at least 140 GPa is used. A rope containing 9% by weight or more.

The use of the lubricating component in the present invention is particularly important in the present invention, and is used for the purpose of improving flex fatigue resistance and weather resistance. Examples of the lubricating component used in the present invention include vegetable oils, waxes, mineral oils, electrical insulating oils, aliphatic esters, aromatic esters, phosphates, polyhydric alcohol-based esters, antioxidants, etc. It is not limited to. Further, in order to sufficiently protect the yarn surface, at least 0.9% or more of lubricating component is required. If the lower limit of this requirement is not satisfied, migration in the twisting process is delayed and stress concentration is likely to occur on some fibers in the finished rope.

The polybenzazole fiber of the present invention is a fiber made of polybenzoxazole or polybenzthiazole, or a random or block copolymer thereof. The tensile strength is 4.0 GPa or more, preferably 4.5 GPa or more, and the initial tensile elastic modulus is 140 GPa or more, preferably 150 GPa or more.

However, although the polybenzazole fiber of the present invention has a high strength and a high elastic modulus, it is susceptible to damage such as fibrillation against the stress applied from the side of the fiber, like the aramid fiber of the conventional material. . Therefore, it is not enough to simply increase the fiber convergence and reduce the friction with the metal, and it is not enough for the fibers to easily concentrate the sliding stress when an external force is applied to the fiber bundle. It is important to make the most of it. For that purpose, it is preferable to provide at least 0.9% by weight, preferably 1.0% by weight or more, and more preferably 2.0% by weight or more of a lubricating component.

The lubrication component may be applied to the fibers by a method such as a method of applying the fibers at the stage of producing the fibers, a method of impregnating or coating the obtained fibers or rope, and the like. In order to fill the components, a method of producing the fiber or a method of directly applying to the obtained fiber is preferable.

By covering the surface of the polybenzoxazole strand to which the lubricating component has been added according to the present invention with a resin after steel making, it is possible to enhance the gathering property of the rope. A method of impregnating the rope surface with a polyurethane elastomer resin is effective for the purpose of improving the unraveling resistance of the rope surface and the stability of the surface state. As a method for coating the resin, a known method can be used. Particularly, in order to improve the adhesive force between the polybenzoxazole fiber and the resin, pretreatment such as corona treatment or plasma treatment of the fiber is preferable.

The rope may be composed only of polybenzazole fiber, but by coating the outermost layer of the rope with a braid of metal or organic fiber in one layer or in multiple layers, the mechanical strength of the polybenzoxazole core wire is increased. Sufficient protection from external forces is possible. The braid that protects the rope is steel wire,
Examples include metal fibers such as stainless steel wire or thick spun yarn, ester, nylon and the like, but the present invention is not limited thereto. In particular, by covering with a braid of Taslan-processed yarn of polyester filament, the handling is good and the durability of the rope surface is increased.

[0013]

EXAMPLES Hereinafter, the method for manufacturing the rope of the present invention will be specifically described with reference to examples. The strength and elongation characteristics of the raw yarn are JIS-
The method of L-1013 (1984) was followed. The strength and elongation characteristic of the rope was in accordance with the method of JIS-L-2707 (1984).

Examples 1 to 4, Comparative Examples 1 to 2 1500 Denier strength 5.2 GPa Elastic modulus 160 GPa
The polybenzbisoxazole raw fiber of 1 was mixed to form a strand, which was processed into a four-strand rope having a thickness of 12 mm. The lubricating components shown in Table 1 were added before the raw yarn was twisted. When the amount of the lubricating component was less than 0.9%, damage was caused when the rope was processed and the weather resistance was lowered.

[0015]

[Table 1]

Example 5, Comparative Example 3 Using the polybenzbisoxazole fiber of Example 1 processed by adding 1% of coconut oil and a commercially available aramid (Kevlar 49) (denier, filament) as a comparative product, A 4 mm triple striking rope was made. Table 2 shows the characteristics of the rope. INDUSTRIAL APPLICABILITY According to the present invention, not only extremely high strength ropes, but also highly safe ropes with little elongation under a large load can be obtained.

[0017]

[Table 2]

Example 6 1500 denier strength 5.2 GPa elastic modulus 255 GPa polybenzbisoxazole fiber processed by adding 1% of coconut oil was used to prepare a 4 mm triple striking rope. Table 3 shows the characteristics of the rope. According to the present invention, a rope which is not only extremely high in strength but also extremely high in dimensional stability with little elongation even under a large load can be obtained.

[0019]

[Table 3]

[0020]

EFFECTS OF THE INVENTION According to the present invention, it is possible to reduce the damage at the time of processing into a rope and obtain a rope excellent in weather resistance and practical characteristics.

Claims (1)

[Claims] 1. A polybenzazole fiber having a tensile strength of at least 4.0 GPa and an initial tensile modulus of at least 140 GPa is used, and a lubricating oil or fat or resin component is contained in an amount of 0.9 wt% or more between the fibers. rope.